A retrospective study of 109 patients who underwent renal biopsy was designed to correlate the sonographic appearance of the kidney with the histologic changes and clinical and laboratory findings in various renal parenchymal diseases. The clinical, pathologic, and sonographic data were analyzed blindly and independently by a team from each corresponding discipline. There was no correlation between the specific sonographic appearance and the type of renal disease. There was a significant correlation between renal length and the prevalence of global sclerosis, focal tubular atrophy, and the number of hyaline casts per glomerulus. A significant positive correlation was also found between cortical echogenicity and the severity of global sclerosis, focal tubular atrophy, the number of hyaline casts per glomerulus, and focal leukocytic infiltration. While there was overall significant correlation between the degree of cortical echogenicity and blood urea nitrogen and creatinine concentrations in each group, a wide range of variance was present. It is not currently feasible to distinguish different types of renal medical disorders using diagnostic ultrasound.